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Audi S4 Differential Parts

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Billet Rear Crossmember / Differential Carrier - Street Density

ES#3432222 - 034-505-1000-SD - Billet Rear Crossmember / Differential Carrier - Street Density - Prevents failure of the factory cast aluminum piece - A must-have for drag/road racing - 034Motorsport - Audi

Prevents failure of the factory cast aluminum piece - A must-have for drag/road racing affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
034Motorsport - Corporate Logo
ES#:
3432222
Mfg#:
034-505-1000-SD
Ships in 2 Business Days
$441.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Polyurethane Rear Differential Mount - Black (Track)

ES#4701581 - ELA-10-285 - Polyurethane Rear Differential Mount - Black (Track) - Eliminate excessive rear differential movement! - Verkline - Audi

Eliminate excessive rear differential movement! affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Verkline - Corporate Logo
ES#:
4701581
Mfg#:
ELA-10-285
Ships in 2 Business Days
$325.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Mount Bushing Insert Kit

ES#3161730 - 019208ecs01KT - Rear Differential Mount Bushing Insert Kit - Decrease differential bushing deflection for better drivetrain response! - ECS - Audi

Decrease differential bushing deflection for better drivetrain response! affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!

Brand:
ECS - Corporate Logo
ES#:
3161730
Mfg#:
019208ECS01KT
Ships in 6 Business Days
$126.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Service Kit

ES#4158614 - n90281802ktKT1 - Rear Differential Service Kit - Complete kit with Redline 75w90 fluid with ECS stainless steel magnetic plugs and seals to service your rear differential. - Assembled By ECS - Audi Volkswagen

Complete kit with Redline 75w90 fluid with ECS stainless steel magnetic plugs and seals to service your rear differential. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
For vehicles with Torque Vectoring differentials

Brand:
Assembled By ECS - Corporate Logo
ES#:
4158614
Mfg#:
N90281802KTKT1
In Stock
ON SALE! SAVE 13%
$114.99

This product was last offered at the strikethrough price on
05-02-2026

$100.26 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Partial Replacement

Driveshaft Gasket - Priced Each

ES#258579 - 183521141A - Driveshaft Gasket - Priced Each - Fits the front and rear position - Genuine Volkswagen Audi - Audi Volkswagen

Fits the front and rear position affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
258579
Mfg#:
183521141A
In Stock
$29.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Rear differential lower Mount Bushing

ES#450897 - 8K0599381H - Rear differential lower Mount Bushing - Located under the rear differential towards the front - Genuine Volkswagen Audi - Audi

Located under the rear differential towards the front affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
From production date 4/28/2009

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
450897
Mfg#:
8K0599381H
Ships in 2 Business Days
8% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$111.99

This product was last offered at the strikethrough price on
06-05-2026

$102.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Service Kit

ES#4620705 - G055190A2-1KT - Rear Differential Service Kit - Complete kit with Genuine fluids and magnetic drain plugs to service your rear differential. - Assembled By ECS - Audi

Complete kit with Genuine fluids and magnetic drain plugs to service your rear differential. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
for vehicles without sport diff

Brand:
Assembled By ECS - Corporate Logo
ES#:
4620705
Mfg#:
G055190A2-1KT
In Stock
$97.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Partial Replacement

Manual Transmission/Differential Fluid 75W-90 - One Gallon

ES#2739026 - 57905 - Manual Transmission/Differential Fluid 75W-90 - One Gallon - For use in front & rear open differentials as well as some manual transmissions - Redline - Audi BMW Volkswagen

For use in front & rear open differentials as well as some manual transmissions affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Redline - Corporate Logo
ES#:
2739026
Mfg#:
57905
In Stock
$97.99 USD
Free Shipping

Hex Low Profile Service Sockets

ES#4464389 - AGA-SS-8-14-K - Hex Low Profile Service Sockets - Due to minimal clearance, its difficult to get a hex socket in the gaps to remove plugs on rear differentials, transfer case and other engine drain/fill plugs. - AGA Tools - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Due to minimal clearance, it’s difficult to get a hex socket in the gaps to remove plugs on rear differentials, transfer case and other engine drain/fill plugs. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
AGA Tools - Corporate Logo
ES#:
4464389
Mfg#:
AGA-SS-8-14-K
Ships in 7 Business Days
$169.00 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Service Kit - With Service Tools

ES#4361552 - N90281802KTKT4 - Rear Differential Service Kit - With Service Tools - Complete kit with Redline 75w90 fluid with ECS stainless steel magnetic plugs and seals to service your rear differential. - Assembled By ECS - Audi Volkswagen

Complete kit with Redline 75w90 fluid with ECS stainless steel magnetic plugs and seals to service your rear differential. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
For vehicles with Torque Vectoring differentials

Brand:
Assembled By ECS - Corporate Logo
ES#:
4361552
Mfg#:
N90281802KTKT4
Ships on Jun 23, 2026
ON SALE! SAVE 14%
$161.99

This product was last offered at the strikethrough price on
05-02-2026

$140.06 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Partial Replacement

Billet Aluminum Rear Differential Mount Upgrade

ES#2966690 - 034-505-2019 - Billet Aluminum Rear Differential Mount Upgrade - Installation is very simple, can be performed in minutes, and is completely reversible. - 034Motorsport - Audi

Installation is very simple, can be performed in minutes, and is completely reversible. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
034Motorsport - Corporate Logo
ES#:
2966690
Mfg#:
034-505-2019
In Stock
$117.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Service Kit

ES#3659099 - n10037106KT5 - Rear Differential Service Kit - Complete kit with Motul Gear 300 fluid with OEM Drain/Fill plugs to service your rear differential - Assembled By ECS - Audi Volkswagen

Complete kit with Motul Gear 300 fluid with OEM Drain/Fill plugs to service your rear differential affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!

Brand:
Assembled By ECS - Corporate Logo
ES#:
3659099
Mfg#:
N10037106KT5
In Stock
ON SALE!
$89.99

This product was last offered at the strikethrough price on
05-02-2026

$88.15 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Partial Replacement

MT-85 75W-85 GL-4 Gear Oil - 1 Quart

ES#2847948 - 50504 - MT-85 75W-85 GL-4 Gear Oil - 1 Quart - Synthetic gear oil for superior performance in your differential - Redline - Audi Mercedes Benz

Synthetic gear oil for superior performance in your differential affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
Redline - Corporate Logo
ES#:
2847948
Mfg#:
50504
Ships in 7 Business Days
$25.99 USD
Free Shipping
on orders $49 and up

Street Density Rear Differential Bushings - Pair

ES#3176342 - 034-505-2001-SD - Street Density Rear Differential Bushings - Pair - Eliminates excessive rear differential movement and provides quick feedback - 034Motorsport - Audi

Eliminates excessive rear differential movement and provides quick feedback affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
034Motorsport - Corporate Logo
ES#:
3176342
Mfg#:
034-505-2001-SD
In Stock
$44.00 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Fill & Drain Plug (M16x1.5)

ES#288792 - 0AA409057 - Fill & Drain Plug (M16x1.5) - Differential fill & drain plug - Genuine Volkswagen Audi - Audi Volkswagen

Differential fill & drain plug affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
For axle code letter HNL, HNP, JKN

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
288792
Mfg#:
0AA409057
In Stock
37% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$37.99

This product was last offered at the strikethrough price on
05-05-2026

$23.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Rear Differential Carrier Mount Insert Kit

ES#2873006 - 034-505-2015 - Rear Differential Carrier Mount Insert Kit - Installation is very simple, can be performed in minutes, and is completely reversible. - 034Motorsport - Audi

Installation is very simple, can be performed in minutes, and is completely reversible. affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

Brand:
034Motorsport - Corporate Logo
ES#:
2873006
Mfg#:
034-505-2015
Back Ordered
Auto Notify
$123.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

More About Differential Parts

Stock or limited-slip, we stock bearings, repair parts, complete differential units, and approved differential fluids so you can keep sending power to the axles without noise, harshness, or vibration.

Let us help you find the parts that fit your Audi

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Manufacturer names and/or part numbers are used only for identification purposes.

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